This invention relates generally to converting sensed signals, such as acceleration and pressure, to a desirable form of electrical signals.
Sensors, such as impact sensors, may be used in a variety of applications, such as automotive airbag systems to protect passengers during collisions. Impact sensors, for example, may employ a variety of sense elements, such as dual capacitive sense elements or single capacitive sense elements. Sensing circuits that interface with dual capacitive sense elements may be less vulnerable to noise such as electromagnetic interference noise or power supply noise, partly because of the differential nature of the sensing circuits. While such differential sensing circuits may be less susceptible to noise, they tend to be rather expensive.
A more cost efficient approach may be to use single-ended circuits, which typically interface with single capacitive sense elements. However, single-ended circuits generally tend to be more susceptible to noise.
Thus, there is a need for a cost efficient way that may be less susceptible to noise to convert sensed signals into a desirable form of electrical signals.